Multivirus Detection from Japanese Landraces of Potato by Reverse Transcription–Polymerase Chain Reaction–Microplate Hybridization

In Japan, 12 viruses have been identified as causal agents of virus diseases of potato: Alfalfa mosaic virus , Cucumber mosaic virus , Potato aucuba mosaic virus , Potato leafroll virus (PLRV), Potato mop - top virus (PMTV), Potato virus A (PVA), Potato virus M (PVM), Potato virus S (PVS), Potato virus X (PVX), Potato virus Y (PVY), Tomato ringspot virus (ToRSV), and Tomato spotted wilt virus (TSWV). In a preliminary survey for viruses using ELISA, we found numerous virus species in landrace potatoes but only a few, e.g., PVY, in commercial ware potato crops. We have now modified a reverse transcription–polymerase chain reaction–microplate hybridization technique, developed for PVY, PLRV, and PMTV, to assay for the 12 viruses referred to above simultaneously. In leaf samples from 35 landraces, PVM, PVS, PVY, PLRV, PVA, and PVX were detected in 94%, 91%, 80%, 77%, 57%, and 43% of the landraces, respectively. These results indicate that potato landraces can act as a reservoir for these viruses with some landraces being asymptomatic. It is thus important to inspect and test for these viruses in seed potato production.